Suppressing STAT3 activation impairs bone formation during maxillary expansion and relapse

Abstract Objectives The mid-palatal expansion technique is commonly used to correct maxillary constriction in dental clinics. However, there is a tendency for it to relapse, and the key molecules responsible for modulating bone formation remain elusive. Thus, this study aimed to investigate whether signal transducer and activator of transcription 3 (STAT3) activation contributes to osteoblast-mediated bone formation during palatal expansion and relapse. Methodology In total, 30 male Wistar rats were randomly allocated into Ctrl (control), E (expansion only), and E+Stattic (expansion plus STAT3-inhibitor, Stattic) groups. Micro-computed tomography, micromorphology staining, and immunohistochemistry of the mid-palatal suture were performed on days 7 and 14. In vitro cyclic tensile stress (10% magnitude, 0.5 Hz frequency, and 24 h duration) was applied to rat primary osteoblasts and Stattic was administered for STAT3 inhibition. The role of STAT3 in mechanical loading-induced osteoblasts was confirmed by alkaline phosphatase (ALP), alizarin red staining, and western blots. Results The E group showed greater arch width than the E+Stattic group after expansion. The differences between the two groups remained significant after relapse. We found active bone formation in the E group with increased expression of ALP, COL-I, and Runx2, although the expression of osteogenesis-related factors was downregulated in the E+stattic group. After STAT3 inhibition, expansive force-induced bone resorption was attenuated, as TRAP staining demonstrated. Furthermore, the administration of Stattic in vitro partially suppressed tensile stress-enhanced osteogenic markers in osteoblasts. Conclusions STAT3 inactivation reduced osteoblast-mediated bone formation during palatal expansion and post-expansion relapse, thus it may be a potential therapeutic target to treat force-induced bone formation.

HIV testing and associated factors among technician school students in Guangzhou / 中国学校卫生

Objective@#To provide data support for AIDS prevention and control by investigating HIV testing among technician school students in Guangzhou.@*Methods@#A total of 1 112 students were investigated with a questionnaire about AIDS knowledge, attitude, sexual behavior and HIV testing through a stratified cluster random sampling method in October 2018. A Logistic regression analysis was conducted for influencing factors of students’ HIV testing.@*Results@#The HIV testing rate of technician school student was 10.3%. The HIV testing rate (12.1%-24.3%) of male, under 18 years of age, with monthly living expenses over 3 000 yuan and with poor family atmosphere was higher than that of the corresponding group (6.6%-8.4%), the difference were statistically significant (χ2=12.07,7.25,10.73,9.77, P<0.05). Multivariate Logistic regression analysis showed that <18 years of age, willingness to participate in relevant AIDS prevention activities, homosexuality, “support for multiple sexual partners” and having sexual behavior were associated with more HIV testing(P<0.05).@*Conclusion@#The incidence of sexual behavior of students in technician school is high while the rate of HIV testing is low, especially for male and male homosexuals.The health and education departments should strengthen students’ AIDS counseling and testing services and raise students’ awareness of AIDS risk in order to improve the coverage of students’ HIV testing.

Trapa natans pericarp extract ameliorates hyperglycemia and hyperlipidemia in type 2 diabetic mice

Abstract The pericarp of Trapa natans L., an annual aquatic floating herb belonging to Lythraceae family, is used as a folk medicine in China. In this study, extracts of Trapa natans pericarp were tested both in vitro and in vivo through a high-fat diet with a single medium dosage streptozotocin injection induced type 2 diabetic mice. Different solvent extracts of Trapa natans pericarp showed α-amylase and α-glucosidase inhibitory activity. After four weeks administration, the ethyl acetate extract of Trapa natans pericarp (50 and 100 mg/kg b.w.) reduced fasting blood glucose level, ameliorated oral glucose tolerance and insulin resistance, improved serum lipids alterations in type 2 diabetic mice as well. Additionally, ethyl acetate extract significantly elevated the insulin receptor substrate 1 and Akt serine/threonine kinase phosphorylation compared to diabetic group. HPLC-MS and HPLC-DAD analysis showed that the ethyl acetate extract was rich in hydrolysable tannins. Results support the notion that Trapa natans pericarp extract has a potential hypoglycemic activity.